WASHINGTON – The number of days with extreme precipitation has increased more in the Northeast than in any other region of the country, a new White House report on the impact of climate change found.

"Heat waves, coastal flooding and river flooding will pose a growing challenge to the region's environmental, social and economic systems," says the third National Climate Assessment, released Tuesday.

Among the challenges: the spread of deer ticks, which carry Lyme disease, and Asian tiger mosquitoes, which carry West Nile virus.

The last White House climate report was issued in 2008, three years before Hurricane Irene severely damaged upstate New York and four years before Superstorm Sandy battered coastal areas. Parts of the Hudson Valley were hit by both storms. Irene and Sandy were "teachable moments" that demonstrated the region's vulnerability to extreme weather events, the report says.

"Whether you want to call it climate change or something else, you have to be prepared," David Wolfe, a professor of horticulture at Cornell University and one of the report's authors, said in an interview. "The impacts are being felt more locally. It's been hard for people to wrap their minds around global change and something happening to polar bears in the Arctic."

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The rain doesn't stop a pair of dedicated fishermen from trying their luck in the Croton Reservoir off Route 100 in Somers April 30, 2014.(Photo: Frank Becerra Jr./The Journal News)

The report's chapter on the Northeast — authored by experts from Nature Conservancy, Bermuda Institute of Ocean Sciences, Columbia University, Penn State and other universities — found plenty of local examples of climate change's impact.

In broad terms, temperatures in the 12 Northeast states from Maine to West Virginia and Maryland rose by almost 2 degrees Fahrenheit from 1895 to 2011. Annual rainfall increased by 5 inches, and the local coastal sea level rose almost 1 foot since 1900, exceeding the global average by 8 inches.

The difference in sea level change between the Northeast and other parts of the world could result from a geological downward shift in land mass — known as subsidence — or a weakening of the Gulf Stream, or both, the report says. It predicts sea level change in the region will continue to outpace the global average.

Climate change will affect the Northeast — and New York in particular — in a variety of ways.

Health issues

• The number of days in the ragweed pollen season has increased as ragweed's range has moved north. The deer population that serves as a host for deer ticks carrying Lyme disease has increased, probably due to milder temperatures.

• Up to 30 million people in the region could be exposed to West Nile virus by the end of the century due to an expanding habitat for Asian tiger mosquitoes.

• An increase in extreme heat events, especially in cities with high concentrations of ground-level ozone, poses a risk to vulnerable groups such as the elderly, young children and people with chronic illnesses such as asthma.

Infrastructure expenses

Superstorm Sandy's flooding of New York City's subway system, Metro-North Railroad tracks and other transportation infrastructure revealed the need to reinforce that infrastructure in preparation for another hurricane of similar magnitude. Likewise, the expected increase in heavy precipitation means even small towns and villages need to prepare to deal with future flooding.

Agricultural problems

• Almost half of New York's apple tree blossoms died in 2012 when they were hit by a freeze after a warm spring caused them to bloom earlier than usual. Wolfe said this past winter's polar vortex hurt the state's wine industry, damaging 30 percent to 50 percent of European varieties of grapevines such as Rieslings. More winter-hardy varieties such as Concord grapevines largely survived.

• Generally milder temperatures in previous winters allowed the survival of a greater number of destructive insects such as the flea beetle, which carries a bacterial disease that damages corn crops.

• Though the number of days of heavy precipitation is projected to increase in winter and spring, it is expected to be followed by a rise in droughts in summer and early fall.

• Cornell University's research on rainfall, which was not part of the report, found the number of average days yearly with at least 2 inches of rain increased from one day in the 1950s to more than six since 2010.